


the first rule of being a magician

by chuuyaya



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Alternate Universe - Modern Setting, Angst, Canon Compliant, College, Domestic Fluff, Fluff, Lots and lots of Pining, Love Confessions, M/M, Mutual Pining, Overuse of Psychological Theories, SenGen meets each other before petrification, Slow Burn, Time Travel, kind of, literature references
Language: English
Status: Completed
Published: 2020-06-29
Updated: 2020-07-07
Packaged: 2021-03-04 05:46:41
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 15,524
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24978634
Author URL: https://archiveofourown.org/users/chuuyaya/pseuds/chuuyaya
Summary: Gen opens his eyes and lists down the facts.One, his hair was back to its natural color and the contrasting dark black hair and light blue eyes makes Gen stop for a second. Two, he was in a room full of props and costumes and he vaguely remembers it as one of his dressing rooms before. Three, yesterday Senku had given him a stack of cards not knowing it was Gen’s birthday and Gen thought,I wonder what would happen if we met 3,700 years ago, Senku-chan.Four and probably the most important one, he went back in time—3,700 years ago.
Relationships: Asagiri Gen/Ishigami Senkuu
Comments: 31
Kudos: 409





	1. the first rule of being a magician

**Author's Note:**

  * For [aizucream](https://archiveofourown.org/users/aizucream/gifts).



> hi emi!! i hope i did justice??? idk if i did??? i'm sorry for wasting your money <3333
> 
> first fic for sengen???? hopefully not the last???? if i can nail their characterizations????

**the first rule of being a magician**

*

Human minds are the most complex yet fickle things.

Gen knows this of course and he uses it to his utmost advantage like the opportunist he was raised to be. It’s easy to let people fall into the trap that’s called his magic tricks and even easier to fool people into believing them.

Lies, after all, are the foundation of how Gen grew up with and at this point, it’s easier for him than breathing. It came to the point where Gen was fine with lying to himself—and that too, came as naturally as breathing.

 _First rule._ Gen says, breathing out as he tries to calm himself. He sees his reflection in the mirror and thinks of how disappointed his past self would be if he saw him breaking the rule now and just because he saw the color of his hair. Unlike what he was used to, dual-toned and contrasting each other, Asagiri Gen stares at his reflection and sees the all-black natural hair he used to have when he was eighteen.

Gen closes his eyes, breathes in. Out.

He tries to rack his memory for the last thing he remembers—stars, Senku, a deck of cards and Gen thinking— _oh_. There was no way, right? He couldn’t have. God, if there ever was one, wasn’t this cruel—but Gen thinks of how humanity went to a stop for 3,700 years and thinks, God if there ever was one was cruel.

_First rule._

He opens his eyes and lists down the facts. One, his hair was back to its natural color and the contrasting dark black hair and light blue eyes makes Gen stop for a second. Two, he was in a room full of props and costumes and he vaguely remembers it as one of his dressing rooms before. Three, yesterday Senku had given him a stack of cards not knowing it was Gen’s birthday and Gen thought, _I wonder what would happen if we met 3,700 years ago, Senku-chan._ Four and probably the most important one, he went back in time—3,700 years ago.

A time where humanity wasn’t petrified and Asagiri Gen was working to climb the ladder of show business.

A time where industrialization was at its peak and Asagiri Gen had access to almost everything.

A time where Asagiri Gen was alone and—

A time where he hadn’t met Ishigami Senku.

*

Gen goes through with his show like a robot performing magic tricks. It’s not like his audience have noticed, of course, not when Gen has mastered the art of lying and misdirection yet his mind was never on the show. He goes through the routines, the tricks and yet his mind conjures an image of wide-eyed and interested Suika asking Gen to show her magic tricks and no matter how many applauses he heard or how loud the audience was, Gen wishes for nothing but a small girl looking at his magic tricks with rapt interest and even wider smile.

Attachment was a messy thing. It always was for Gen. He knows he has a whole suitcase to unpack, especially on that certain aspect, but the baggage is far too much and it’s easier to throw the whole suitcase away—or bury it for that matter.

Buries the feeling that rises when he remembers old man Kaseki, dragging Gen to whatever Senku had assigned him to, claiming that Gen should accompany a helpless old man even when both of them know he isn’t and there are plenty others out there but he still chooses _Gen._

Buries the laughter when he remembers Ryusui and how greedy he was making it easy for Gen to make him dance to his will according to what Senku wanted.

Buries the emotions bubbling when he remembers Taiju and Yuzuriha—two of Senku’s oldest and most loyal friends, who stood by Senku without Senku asking them to, Taiju: who could brighten up the room with his shouting and never-ending energy and Yuzuriha: kind yet deadly Yuzuriha who was the heart of the three. And Senku—

 _God._ Ishigami Senku. Gen buries the feelings that’s been there ever since he saw that mark on the tree, buries the feelings that only seemed to grow as he stayed longer on Senku’s side, buries the feelings that’s about to burst every time he thinks of Senku. Ishigami Senku who said he would revive humanity, who refused to kill anybody, who built everything from scratch, who said he would only build things that they needed but went out of his way to give the villagers a stove for winter, agriculture to combat famine, show them the lights of the modern world among other things and Ishigami Senku who Gen loved with everything in him.

To be fair, it’s not hard to love Senku, of course not—not when Senku was like the sun, burning so brightly in the sky and Gen stares at him unafraid. Not when Senku bleeds kindness but shows it in his own ways, not when Senku tries to carry the burden and guilt all by himself and sometimes Gen wishes he could take those pain away and Gen wasn’t the master of human psyche if he does not recognize his own feelings and yet—yet he was always pushing those emotions down because he couldn’t tell Senku knowing that Senku was drowning with so many burdens on his shoulders and he couldn’t add on to another one _(—or maybe that had been a flimsy excuse because of how afraid he was but now—)_

Now, Ishigami Senku will never find out how much Gen loves him because in this world, their paths would never cross and Senku would never be interested in Gen.

“Gen, you okay? You’ve been spacing out ever since earlier?”

“I am,” Gen says, smiling at his manager. _First rule._ He looks at the window, watching as their car pass by the familiar streets that Gen hardly remembers after being subjected to the Stone World for so long. “It’s nothing, Hayashi-chan.”

“Did you enjoy performing the show?” His manager grins, not even seeing through the crack of Gen’s mask. “It’s your birthday today after all and you’ve sold out. How do you feel?”

“It pales comparison.” Gen whispers to himself and thinks of the warmth of having Senku close, thinks of the fun times he had with the Five Generals, thinks of Suika and the villagers, thinks of the whole Kingdom of Science and—

Gen was supposed to be a shallow man. He was supposed to do things for his own benefit and for him to gain anything he wanted. He acted for the betterment of himself and for his own advantage. Gen was supposed to be the most superficial human and yet, no matter how many times he tries to distance himself, to be a blurry glass to others, Gen finds himself slowly he growing attachment—to the villagers, to Suika, to Kohaku, to old Man Kaseki, to Ryusui, to Ukyo, to Chrome until his feet had rooted on these people, unable and unwilling to leave, until he could feel himself slowly giving them a space in his shallow heart, until his love for Ishigami Senku grew and he could no longer contain it.

Gen _was_ supposed to be the most superficial man and yet in just one lifetime in which he had Senku and the others, Gen cannot find it in himself not to care about them.

“Ah,” Gen chuckles to himself, feeling his eyesight go blurry. _First rule, Gen._ “It really does pale comparison.”

Once he arrives on his apartment, Gen feels like a stranger. The apartment that littered with his things felt like it belonged to someone else. There’s Gen’s bookshelf on one corner, full of psychology and magic books but Gen thinks it’s missing drawings and diagrams of inventions. There’s Gen’s coat on the back of the couch but as Gen fiddles with it, he realizes that it isn’t warm or soft enough.

As Gen walks through the apartment that used to be his home, Asagiri Gen feels alone again.

*

Gen, if nothing else, was a realist. Sure he loved doing magic and tricks and it’s mostly based on imagination, ideals, and deception but Gen knows when to abandon the ship, knows when to push his cards and pull them away, knows when to give up and when not to.

So Gen lists out the things he knows—one, he wasn’t dreaming about the Stone World and everything really did get petrified. Two, he doesn’t know if there’s a chance it would happen again because he does not know how he came back in the first place. Three, he could never get that warmth of the Kingdom of Science back, not when the Ishigami villagers—Kohaku, Chrome, Old Man Kaseki—won’t exist until far far _far_ in the future and the rest of them don’t know who Gen was. And lastly, there was no way Asagiri Gen and Ishigami Senku’s paths would cross in this life.

He’s stuck on a standstill, unable to move forward or back. For the first time in his life, Gen doesn’t know what to do.

Should he wait for the petrification again? Would the petrification occur again? ~~Would he be able to meet Senku in this lifetime if not for the petrification?~~

Trying to find Senku through high school was out of the option. There were too many public and private schools and even if Gen did manage too narrow it down, there was the fact that Ishigami Senku does not know him and although Gen could lie through his teeth—he never wants to lie to Senku, not ever again.

Gen tries to look for Senku in the internet (—god, he had missed having information at the tip of his fingers because while Senku was a walking encyclopedia, Gen unfortunately, was not) but the only results are piano music composed by African Descent, a CD on Amazon and some seminars about cultural history.

Groaning, Gen rubs his fingers on his face, flopping down on the bed. “You really are an ard-hay man to find, Senku-chan.”

Giving up wasn’t an option. If Senku were here, Gen knows the last thing he’d do was give up.

 _Yet you aren’t Senku,_ a traitorous voice in his mind whispers. _You’re only Gen._

Gen curls up on his bed. The sheets are warm and it’s bigger than what he had on the stone world but for some reason, it feels so cold.

Gen closes his eyes and hopes that their warmth returns.

*

It seems funny now, Gen realizes, how without the world being petrified all of them might never come across each other’s paths. Senku would never be interested in Gen’s work because he was far too logical to watch Gen’s shows, probably claiming him to be a fraud. Ryusui was too rich and too high up the social ladder for them to reach. Ukyo was reserved and there was no way a sonar man like him would be interested in magicians, students (—even if said student is a genius) and a rich boy. Chrome, well, without the petrification, Chrome might never have been born.

Gen tries to take on more work, show after show, performance after performance that his bank account was probably rolling with how much he works and how little he spends on it but all the work that leaves him tired and weary makes him unable to think of the stone world, of the Kingdom of Science, of the Five Generals—of the family that Gen thought he’d never get to have.

Because if he stops, even just for a moment, he remembers the feeling of being given a second chance at family, remembers the inventions and disasters that they’ve went through, remembers the misunderstandings and fights that ended up in laughter and smiles, remembers the warm fuzzy feeling he gets whenever he looks at all of them.

Because if he stops, Asagiri Gen would be reminded of how lonely he is.

Unlike some people, loneliness had accompanied Gen throughout his life. With workaholic divorced parents, no friends in high school since he got scouted at an early age, mere acquaintances in show business because Gen could see through their fakes smiles and knows they would step on Gen if they ever feel that Gen was a threat, Gen was no stranger to loneliness. He should be used to it. He should be fine but there’s a kingdom shaped hole in his heart—one that aches every single day as he opens his eyes and sees the fully-furnished apartment, one that twinges every time Gen sees a melon or a stone for that matter, one that pangs whenever Gen hears the word _exhilarating_ , one that throbs every time Gen looks at the ships in the sea.

Loneliness should be his childhood companion but the shadows of his childhood companion was slowly getting engulfed with the light as the Kingdom of Science grew and life is nothing but cruel. This is why Gen doesn’t want to get attached. This is why he prefers to put a distance on himself and people because losing people and getting left behind was far too painful for Gen to endure.

“Gen, you’ve been working too hard these past few days.” Hayashi says, coming up from behind him with a frown on her face. “Are you sure you’re okay?”

Gen waves her off. “What’s my next appearance, Hayashi-chan?”

Hayashi stares at him in concern for a moment before she sighs. “It’s a special TV show called Mentalist Battle. You’re one of the special guests along with a few others.”

“Mentalist Battle?” Gen asks, trying to rack his brain to where he heard that. The TV? No. Gen doesn’t use the television as much as he does, opting to use his laptop to search for updates about his friends: Ryusui bought another game company for some reason? There’s no updates about Ukyo, nothing about Senku or Taiju or Yuzuriha and Tsukasa—

Tsukasa. Mentalist Battle.

Then it clicks. He was going to meet Tsukasa in the Mentalist Battle.

Gen hasn’t seen anyone he knows in the Stone World and he nibbles his lower lip, trying to school his expression at the thought of meeting Tsukasa again. Does he remember, like Gen does? It’s a possibility but Gen also knows that it’s almost next to impossible.

 _Nothing’s impossible, mentalist._ He hears a familiar voice in his head. _Science, hard work and perseverance and you can make anything possible._

For the first time since he was stuck in a standstill, Gen feels himself slowly walking forward, even if it’s just a small single step.

The TV show was sort of a fraud—if Gen was to put it in Senku’s words. Aside from the special guests, everything was scripted. After all, reality TV shows are far more superior in terms of acting than other actors.

Gen goes through a flurry of magic tricks, showing the world the mastery of his sleight of hand. He could feel the excitement thrumming in his veins, feeling like his heart was about to hammer against his chest at the thought of seeing someone familiar. Gen doesn’t remember doing much on the show but he remembers when the curtain opens showing Tsukasa standing there with his boxing gloves.

It makes Gen’s breathing hitch and he reminds himself that he was in a room full of cameras.

_First rule._

This time, Gen doesn’t need to fake a smile. He looks at Tsukasa and thinks of the amount of times Tsukasa had saved his life (—except for those times in the Tsukasa Empire because Gen felt nothing but safe), thinks of the times Tsukasa had Senku’s back (—he did kill him once and tried to do it again but all in the day’s work), thinks of the times when they traveled Perseus together overcoming every obstacle in the way with Tsukasa’s strength, Senku’s brains and Gen’s manipulation.

For the first time, Gen feels like he can breathe again.

He looks at Tsukasa and in the same moment, Tsukasa turns to meet his gaze. Like the first time Gen saw him, Tsukasa’s amber eyes glinted with fierceness and determination. He looked intimidating paired up with the fact that he could wrestle a lion barehanded and come out unscathed but that isn’t what makes Gen stop.

He had his hopes, of course—that he wasn’t the only one sent back, that the Kingdom of Science was still here even in the modern world, that his friends would remember him. He knows, even if he tries to tamp it down and tell himself to be realistic, that there was always a part of him that clung into that hope and now—

Now, Gen feels like everything comes crashing down, like he was stuck in a standstill not knowing where to go, like someone had crushed the tiny bit of hope that Gen still had left.

Because when Tsukasa met his gaze, there was no recognition in his eyes. He merely glances at Gen before talking to another person in the show.

Gen tries to calm himself. _First rule._ He breathes in. Out.

In. Out.

 _You expected this._ He thinks with a sardonic smile. _Why are you so disappointed now?_

Gen feels like dissociating, feels like sinking into a soft warm mattress with no one to hold into. He tries to ground himself—one, two, three, four—but he was never as good as counting as Senku and that only reminds him more of the Stone World than in the reality he is in now. He doesn’t remember what happens, doesn’t know how he managed to finish the show but as soon as it does, Gen remembers running to the toilet and puking the dinner he just ate.

“I’m really alone, huh.” Gen smiles bitterly as he stares at his reflection in the mirror. Pale. Horror stricken face. “I’m alone, again.”

Gen waves off his manager’s concern, feeling like a puppet on strings as he gathers up his things and leaves the show. He walks to his apartment, feeling like he needed to ground himself before he dissociates.

Streets. Lights. Buildings. Arcades. Movies.

He notes every single thing he sees, reminding himself that this was the modern world. When he glances upon one shop, Gen remembers the numbers like it was as clear as day. Without thinking much, Gen enters the shop, the soft chime of the bell makes the person on the counter look up.

Gen puts the mask on his face. “Do you accept walk-ins?”

“Sure.” The guy says, shrugging. “My next appointment is three hours from now anyway. Do you already have something in mind?”

Gen nods. He sketches it on the piece of paper, unable to forget about it.

The guy hums. “Where do you want it?”

“Right here.” Gen replies, patting the left side of his chest, just below his collarbones. “It won’t take long right?”

“No.” The guy shakes his head. “But it will hurt like a bitch since it’s near your bones.”

“That’s fine.” Gen says, closing his eyes. He wants to stay grounded. It’s a reminder, for him.

The process is painful but Gen manages to endure it all the way. It felt like hours but as the time passes by, Gen feels more and more like himself. He was Asagiri Gen, the shallowest man on Earth, opting only to save himself above others. He is Asagiri Gen, master of the human psyche, magic tricks, manipulation and sleight of hand. He is also Asagiri Gen, one of the Kingdom of Science’s Five Generals—who explored the world together with the greatest scientist Gen knows as they try to revive humanity.

“Remove the bandage after 24 hours.” The guy says. “Wash it gently with soap and just pour some antibacterial ointment once a day.”

Gen nods. “Got it.”

He is Asagiri Gen and he doesn’t want to give up.

Dialing a number he had memorized for years, Gen waits for his manager to answer the phone. Humming, he looks at the city, trying to commit the sight on his memory. “Hello, Hayashi-chan. I’ve got an uestion-qay~”

“Gen?”

“How much is the passing rate for Kyushu University?”

He is Asagiri Gen and he will find Ishigami Senku.

*

By process of elimination, Gen knows the closest thing he could find Senku would be in Kyushu University. Going abroad was out of the question and Kyushu was the top school in Japan for Aerospace Engineering. Gen still has to wait for a year before he can find Senku again but its fine. He’s been petrified for 3,700 years before, waiting is a piece of cake compared to that.

Well, his plan could go all for naught if Senku decides to go abroad but Gen’s ten billion percent sure he wasn’t going to and he can’t go directly to NASA, no matter how much of a genius he is, without a degree and besides, there’s no chance that Senku would miss using Kyushu’s resources for his own experiments.

Every day, Gen wakes up fearing that he might’ve turned to stone in his sleep.

Classes, if nothing else, are boring for Gen. Psychology, after all, is amazing when it’s applied but the theories behind it makes Gen’s head hurt. Having to learn about Freud and his contributions to the field of Psychology drains the hell out of Gen. It’s a pity he’s the most famous psychologist when all his works were all about libido and sex in general.

Sighing, Gen opens the door to his room. Kyushu’s dorms were expectedly big and private, soundproof too for some reason. Gen feels drained. He flops down on the small sofa, feeling all worn out. It’s been two years and still no sign of Senku or the petrification.

Gen frowns. Did it go away then? There should be a logical explanation for it. If Gen was sent back in time, then why? And was it because he was sent back that the petrification didn’t occur? No. That’s too much speculation. After all, Gen didn’t even try to change much.

“Dearest Senku-chan,” Gen sighs. “I’m not cut out for this theorizing stuff, you know. My talents lie elsewhere.”

“Huh? Did you call me?”

Gen feels like the world had tilted on his feet. For the first time, he notices the boxes on the other end of the room, the thousands of beakers and equipment’s on the table. For the first time, Gen notices that he isn’t alone.

And—he knows that voice.

Gen feels his throat dry, feels dizzy all of a sudden, feels like he’s dreaming because that voice—he’d never forget that voice. It’s the voice of the person Gen trusted with his life, the voice of the person that made Gen feel safe, the voice of the person who refused to harm anybody and proclaimed that he would revive all seven billion humans.

Ishigami Senku was a hard man to forget.

Gen doesn’t think he can ever forget him.

He was leaner and taller than how Gen remembered him but everything else was the same—the same gravity defying hair, the same crimson eyes that seem to burn right through Gen, the same habits as he pokes his hand on his ear as he looks at Gen—and in every lifetime, Senku makes Gen’s breath hitch in awe.

“I wondered why you were familiar,” Senku says, crossing his arms on his chest. “You’re Asagiri Gen.”

“Senku-chan knows who I am?” Gen grins, feeling like he drank five cups of coffee as he looks at Senku. _He’s here. He’s here. He’s right here._ “I’m onored-hay!”

“You wrote those trashy magic books, didn’t you?” Senku says, raising a brow. Gen wants to laugh so he does, hiding it behind his palm. He isn’t a tad bit offended as he remembers the first conversation he had with Senku on the stone world. “And how do you know me?”

“Well…” Gen trails off. “You are Ishigami Byakuya’s son, Senku-chan. He is a famous astronaut, after all.”

Senku hums. “Never thought you’d be the type to be interested in that.”

“How rude,” Gen pouts, crossing his legs on the couch. “Psychology is still science, Senku-chan. Besides, I’m interested in astronomy.”

“Of course you are.” Senku replies, rolling his eyes. “You probably use horoscope to deceive people too.”

“Deceive is such a harsh word, Senku-chan.” Gen sing-sang. He skips to where Senku is, careful to not touch anything accidentally. “What are you making?”

“You’re fine with it?”

“Fine with what?”

Senku scrunches his nose in distaste. “Most people would immediately ask me to transfer rooms when they see experiments such as this, fraud magician.”

“Hey, I’m not a fraud!” Gen whines. “You’re hurting my feelings here, Senku-chan. Of course I’m interested!”

Senku turns to him and again, Gen feels like Senku’s trying to burn through his soul. “You’re interested in experiments?”

“Not really no,” Gen hums as he looks over Senku’s notes. He doesn’t think he can ever understand it but the familiarity of it makes Gen smile. He turns to Senku, licking his lips. “But there is something else I’m interested in.”

Even if this Senku still doesn’t know Gen, Senku knows how to read between the lines. It’s how they managed to coordinate so well before, how they manage to understand each other with just one word, how they manage to know each other’s thoughts with just one look.

“Unexpected.” Senku snorts. He turns to his notebook again before he looks at the things on the table. He points at the circuit board on the table. “See, I’m trying to…”

Gen smiles as he listens to Senku babble on about his experiments. He feels like he’s thrown back in the stone world, watching as Senku explains something Gen can’t understand but still find comfort in Senku’s voice and how Senku was a steady presence beside him.

Even if Senku doesn’t remember him, at least Gen was able to meet him again.

For the first time since he came back, Gen doesn’t feel alone.

*

Living with Senku was easy especially since Gen already experienced it once. He had the tendency to stay up late at night to work on his experiments, had the tendency to forget what he was doing because he was too focused on work, had the tendency to wake up Gen with the noise he makes whenever something breaks—but Gen finds comfort in all of this and merely smiles at Senku’s antics.

“I’m home.” Gen shouts, just as he arrives at their dorm. “Senku-chan, did you go out at all today?”

Senku hums. “Yeah I had one class in the morning.”

“Did you eat?” Gen asks, only to be replied with silence. Rolling his eyes, Gen tugs on Senku’s lab coat. “C’mon, that experiment won’t go anywhere, you need to eat.”

Senku turns to him, probably ready with another excuse but Gen puts his hand on Senku’s mouth, tugging him harder. “C’mon Einstein, that’s not going anywhere and you need to a change of scenery.”

“And that’s our dining table?”

“Yep,” Gen hums, putting the take-out on their table. “Trust the mentalist, Senku-chan.”

There’s something in Senku’s gaze that Gen is unable to read before it goes away replaced by his usual carefree smile. Gen hums, grabbing the plates as Senku arranges their table. They both work in silence yet it’s comfortable and familiar and Gen relishes in how much Senku’s presence gives him comfort.

“Senku-chan, stop frowning on your food.” Gen hums as he sat down across Senku. “I’m not going to make you pay for it, you know.”

“That’s not why, mentalist.” Senku rolls his eyes before picking up his chopsticks and grabbing a piece of meat. “I was just thinking why you’re still here.”

Gen blinks. “Senku-chan, are you trying to get rid of me?”

“That’s not what I mean you and you know.”

Gen hums, a teasing smile on his face. “Do I? I’ve only known you for two months, Senku-chan.”

“If you don’t want to answer then don’t.”

“Always so blunt,” Gen hums. “Why would I leave, Senku-chan? Being with you is interesting.”

“You’ve got shitty taste, mentalist.”

Gen tries to kick him under the table, poking his tongue out at him. “Rude.”

Senku rolls his eyes but Gen could see the smile on his face.

As usual, as soon as Senku finishes lunch, he immediately dives back into his experiments. _Honestly, still the workaholic._ Gen walks to where he was, staring at Senku who was too concentrated on his experiments to notice Gen. Gen takes in the changes that Senku’s had over the years that they haven’t seen each other. Aside from being taller than Gen now, Senku’s features have matured over the years—baby cheeks shaping into a chiseled jawline adding the attractiveness that Senku had, his hair slightly longer, his shoulders broader making him look leaner and fitter in his labcoat.

“What?”

Gen hums. “Nothing. I’m just looking, Senku-chan.”

Senku turns to him, expression deadpan. “You’re distracting me.”

Gen raises a brow, taking in Senku’s words. Senku never says anything he means and there was no way that Senku would be distracted by Gen when he’s focused on his experiments. That wasn’t how Senku worked—

But then, it’s been years since Gen had seen Senku, years since he had talked to Senku, years since he’d been in Senku’s presence.

“Alright, alright. I’ll stop.” Gen laughs. “Want some help?”

At the disbelief in Senku’s face, Gen pouts. “Hey, I’ll have you know that I’m an excellent help! A scientist used to ask my help when he’s making science stuff, you know.”

“Science stuff.” Senku snorts. “Fine, can you give me—”

Gen already knows what Senku wants. After all, he’s seen Senku build this in the stone world. “Here.”

Senku’s brows raise but he doesn’t question it. “Hand over the—”

“Yep, here you go~”

“And the—”

“It’s on your right, Senku-chan.”

Senku turns to him, expression bewildered and confused. Gen knows what he’s about to ask and he merely smiles, waiting for the question. Then, Senku shakes his head, a smile on his face as he turns back to his experiment. “Not bad, Asagiri Gen.”

Gen beams. “Coming from you that’s a compliment.”

Gen doesn’t know how he managed to fall asleep or move into the sofa for that matter but he finds himself waking up with Senku’s lab coat around him. Gen has always been an early riser and reaches for the coat, burying his head as he tries to contain it. Did Senku carry him to the couch? Impossible. His arms would give up halfway.

Laughing to himself, Gen stretches, feeling his muscles pop back into place. He looks down at Senku’s lab coat, an idea forming on his head. Well, it’s not like he’s going to lose anything. Besides, it would be fun to see Senku’s demeanor cracking.

Humming to himself, he goes to the kitchen, looking over their mini-fridge.

He grabs a bottle of coke just as the door opens and Senku’s voice echoes in their room. “Cola isn’t a suitable alternative for coffee—”

Gen turns, raising a brow. Senku’s staring at him, unblinking with his brows raised. Gen stares at him right back, throat dry when he sees what Senku was wearing. A turtleneck. Ishigami Senku was trying to break Gen’s thoughts—not really trying seeing that he’s already doing it but— _a turtleneck._

Senku was wearing a pale brown turtleneck, probably folded once to ensure his breathing paired up with light blue fitting pants and the cherry on top was a brown Burberry coat. Gen blinks. He’s seen Senku wear modern clothes of course—courtesy of Francois and the photograph Minami has but this—seeing Senku wear casual clothes was doing things for Gen’s stomach. He felt like the warm feeling on his gut is spreading, taking control over his whole body the longer he stares at Senku.

Senku clears his throat, his brow still raised. “You’re wearing my lab coat.”

“And you brought breakfast.” Gen replies, not skipping a beat. His mind might be broken right now because _fuck_ , Senku looked so good in modern clothes—but he was still a mentalist, a great one at that.

Senku huffs. “Touché.”

Gen quietly stares as Senku puts the take-out on the table. If Senku notices, he doesn’t try to call out Gen but he does raise a brow at him. Smiling, Gen raises a brow back, still staring at Senku.

“You’re distracting me.”

Gen hums. “Can’t believe the great Ishigami Senku would let someone distract him like that.”

“It’s you.” Senku says, rolling his eyes. He plucks the Cola out of Gen’s hand like he hadn’t dropped words that made Gen’s heart thunder aggressively against his chest. “Cola isn’t an alternative for coffee, mentalist.”

“Yeah.” Gen replies, feeling like his throat had dried up. “Okay, let’s go eat breakfast.”

He ignores the amused snort that he hears out of Senku, for the betterment of his heart.

Ishigami Senku never says anything he doesn’t want to, never says anything he doesn’t mean to. Gen nibbles his lower lip and feels like Senku had tilted his world with those two words.

His heart doesn’t calm down, even when Senku leaves for the day to go to his classes.

*

Gen drops dead on the couch, feeling tired and weary. He knows it’s a bad idea to juggle classes and his work but Gen needs the money to be able to continue university especially since his parents have either stopped caring about him or forgot he existed at all.

His phone vibrates from his pockets, maybe another Google alert of Ryusui’s name or another text from his manager.

God, he still has homework to finish and still think of another magic trick to add to his repertoire for next week. He sighs, closing his eyes and covering it with his arm.

He feels tired and god, he just wants to sleep for like a week.

“Hey mentalist, the couch isn’t good for your back.”

“Mm.”

Gen hears quiet shuffling and Senku’s footsteps before he feels soft hands tugging his wrist. “C’mon.”

Gen hums, eyes still closed. “Tired.”

“It’s better if you’re on your bed.”

“Mm.”

A chuckle. “C’mon. I’ll let you lean on me.”

He tugs Gen harder this time but still so gentle that if Gen was more awake, his heart would probably be beating loudly right now. Gen doesn’t even open his eyes, merely letting Senku’s hand guide him as he leans on Senku’s side, hoping that the man doesn’t shy away from his touch.

Senku’s presence is warm. Comforting. Familiar.

“April 1st, 5738.” He hears Senku say and suddenly, Gen feels awake, his mind halting at the sound of those from Senku’s mouth. No. There was no way—

Gen’s eyes snap open, nibbling his lower lip to meet Senku’s gaze. Senku didn’t recognize him the first time, Gen would’ve seen through him. There was no way he could’ve hidden it from Gen but how— _how does he know that?_

Only Senku, Gen and Tsukasa would’ve known yet Tsukasa was already crossed off Gen’s list when he didn’t recognize Gen the first time they met. Senku hadn’t either and Gen was sure that no one else beside him was sent back in time.

Yet how—

“Does that mean something?”

Gen tries to calm himself and he manages to steady his voice when he asks, “What do you mean?”

“Your tattoo.” Senku says and that makes Gen’s stomach swirl.

_Of course not, Gen. There was just no way for him to remember you._

Gen unconsciously traces the tattoo near his collarbones. Even without the mirror, he can feel the characters, knows them from inside and out, has them memorized and tattooed on his heart—quite literally.

“It’s an important date.” Gen says, exhaustion coming back at him full force. He closes his eyes again, trusting Senku to guide him to his bed. “Someone… important. I miss him. I miss… _them_.”

Senku gently pushes him on the bed. Gen hears the quite shuffle of the sheets and Senku’s footsteps before he feels a warm blanket covering him from his feet to his neck. He feels Senku’s hand covering his eyes and the familiar scent of Senku, those familiar hands on him, Senku’s presence near him—it’s a lullaby for Gen and he passes out after a second.

When Gen wakes up, Senku is nowhere in the vicinity.

Their dorm was quiet, uncharacteristically so, when you have Senku as your roommate. There was already breakfast on the table and Gen knows Senku’s classes don’t start until ten o’clock.

He should be here, tinkering with whatever his hand had found next.

Gen traces his tattoo, the feeling of it making him calmer by the second. He stares at his reflection, staring at the blank-ink _April 1 st 5728 _tattooed near his heart just underneath his collarbones, contrasting the pale white skin.

Should Gen tell him?

Would Senku even believe him?

Senku, after all, was a man of science. Logical. Rational. There was no way for Gen to explain what happened in a logical and rational way. Gen trusts Ishigami Senku with all his heart but does Senku feel the same? Does Gen have Senku’s trust?

They’ve only known each other for almost three months. Would Senku believe him if he told him he’d traveled back in time?

Gen sighs, grabbing his coat as he looks at the time. He has another gig in a few minutes and thinking about Senku is just going to be a huge distraction for Gen. Gen grabs his keys and was about to go out when he sees a bright light from his window.

Furrowing his brow, he looks at it and suddenly—

That was familiar. That green light. He feels his body slowly getting petrified, from his hands to his lower body to his face and all Gen can think about is—

_Oh. I missed the chance to tell Senku I love him._

He should’ve told him, maybe told him everything and this wouldn’t happen.

Gen wants to laugh. There’s no point in this now, isn’t there? Now he has to wait for 3,700 years to make it back to Senku’s side again.

_I really should’ve told him._

Gen falls into the darkness.


	2. is to always have your poker face on

**Summary for the Chapter:**

> “Senku-chan,” Gen says and his voice is uncharacteristically soft and mellow. “The moon is beautiful, isn’t it?”
> 
> Senku stops. Exhilaration. Euphoria. Racing heart. Trembling.
> 
> _Oh._

**Notes for the Chapter:**

> and here's the final chapter! emi i hope you enjoy this <333 senku's pov ha ha i felt like i set myself up for failure but hopefully it won't be too ooc :D
> 
> unedited as usual !! why do i love posting fics at unreasonable hours

*

Ishigami Senku was a man of science.

He was not the kind of person who would jump into conclusions without definite evidence. Hypothesize yes but drawing conclusions would come after the evidence was presented right in front of him. If all his hypotheses were wrong, then it was back to the drawing board. Science, after all, was just a process of trial and error.

However, Senku was ten billion percent sure that there was no logical conclusion as to why Asagiri Gen knew the exact day and the exact year on which he would revive from being turned into stone.

Senku stares at the date he had written in the tree, the familiar numbers flooding in Senku’s head like a well-memorized formula. 117,354,893,880 seconds since he’s been petrified and when he mentally calculates the date in his head, Senku feels like a vein would pop from all the thinking because those numbers; the one that Senku had written on the tree, the numbers that Senku was sure he didn’t make an error in calculating— _April 1 st 5738 _were the numbers written in Asagiri Gen’s chest.

Was it a coincidence? _No._ Senku was ten billion percent certain it wasn’t, not when it was Gen they were talking about. Gen wouldn’t be impulsive in putting something in his body, especially something as permanent as a tattoo. It was too accurate, _too much_ of a coincidence for Senku to wake up in the exact same date as Gen’s tattoo.

 _“It’s an important date.”_ Gen had told him when he had asked about it. _“Someone… important. I miss him. I miss… them.”_

Why hadn’t Senku realized it sooner? 5738—those weren’t just a jumble of numbers, those numbers were the year. April 1, 5738: the exact day and the exact year Senku had revived from the petrification.

The question now was, how did Asagiri Gen know about that?

He feels the cold breeze caress his skin making Senku shudder. _Right._ He was in the primitive world. Every human invention was nowhere to be found, washed away and destroyed by the hundreds of calamities that passed by them during those 3,700 years. Before worrying about anything else, Senku would first worry on how to survive the day.

Take it one step at a time.

Senku buries the thought of Asagiri Gen and his tattoo, tells himself to bring it up when he wasn’t in the face of danger or death anymore, tells himself to forget about Asagiri Gen for a moment and focus on living.

~~(—however, deep down, Senku knew that Asagiri Gen was a hard man to forget.)~~

*

Taiju wakes up six months later and Senku grins, feeling exhilarated. He knew that Taiju wouldn’t go down so easily and against all odds, even with no evidence presented right in front of him except for the fact that Senku _knows_ Taiju and Senku knew that Taiju was going to break free by himself.

It makes things easier for Senku, for both his body and his mind. Before, it usually took him a day to at least procure some food. He wasn’t a miracle worker, after all. He could only do things step by step, with perseverance and his wits. But now, with Taiju on his side, Senku could focus mostly on his experiments and thinking of a number of hypotheses for the petrification incident.

Also, making sure Taiju doesn’t die on accident because he picked up a poisonous plant.

“Look, Senku! Berries!”

Exhibit A.

Senku rolls his eyes and points at the pink berries on Taiju’s hand. “Coriaria japonica, commonly known as doku utsugi.” There’s a pause in Taiju’s movements, tilting his head in confusion as he waits for Senku to explain. “It’s a berry native to Japan but they don’t usually grow near here but the landscape changed after 3,700 years and that berry is poisonous.”

“Oh?” Taiju throws the berries away. “It’s a good thing you’re here then, Senku!”

Senku was never one for sentimentalities. He has a good grasp of his emotions and although he never tries to bury it down, he doesn’t advocate on it either. He prefers to be rational and logical but human beings sometimes make mistakes because of their emotions.

That said, Senku knows he could’ve made it through his life without Taiju but the truth was, he was thankful that Taiju had tried to protect his experiment that day cementing the friendship between them.

 _At last,_ Senku thinks as Taiju gets another empty basket to scavenge them food. _I’m not alone anymore._

*

They revive Tsukasa and it’s safe to say that doesn’t go well for them. When Senku dies, he blames it on his bad luck.

_“Imagine if we woke up a murderer right off the bat.”_

Stupid Senku luck.

When Taiju and Yuzuriha revives him, he’s ten billion percent sure no one else would be able to look at the hidden clues he’s left behind except for those two. Not for the first time and definitely not the last, Senku’s pleased to have met Taiju and Yuzuriha.

Stupid Senku luck indeed.

*

If asked, Ishigami Senku would say he had not thought of Asagiri Gen for the past 427 days since his revival. He has got things to do and there was no use worrying about Gen when he promised himself that he would bring all seven billion people back, Gen included. But in the confines of his own mind, the numbers are rapidly increasing and it’s been 117,391,710,297 seconds ever since he last saw Asagiri Gen—3,700 years ago in their shared dorm room.

Senku has a Kingdom of Science to build and there was a lot to be done before they could go up against Tsukasa. He couldn’t lose focus, not when his life and science was on the line and he never does. During the day, he reinvents humanities inventions, letting Chrome and Kohaku see the two million worth of human discoveries that had been erased by the petrification. He teaches Chrome about the science all cramped in his head—from the chemicals of the periodic table to the use of his large rock collections—and revels in the way Chrome’s brown eyes watches everything unfold in rapt interest. During the day, he focuses on slowly rebuilding civilization back to the modern period, even with the grueling step by step process. It’s slow but it keeps Senku’s mind preoccupied.

During the night, however, was a different story. In the day, at least he can focus on his experiments when his hand is tinkering the items but during the night, his brain is as active as ever—probably due to the whole frozen for 3,700 years thing but still managed to stay conscious—but instead of figuring out how to win the villager’s trust, Senku’s mind—his most powerful tool that enables him to do science—betrayed him by thinking of the things he had tried to bury down in lieu of his survival.

How Taiju and Yuzuriha are faring in the Tsukasa Empire. How long till Tsukasa finds out he’s alive. In the dark nights, he allows himself to think ~~of Byakuya and of Gen~~ of the things Senku had lost.

Senku has always been able to keep his emotions in check and finds the most logical and rational answer no matter how dire and hopeless the situation may be. But quiet nights like this makes Senku remember of Byakuya fetching him from the park when he was young, indulging Senku about the secrets of the universe. Quiet nights like this makes Senku remember Gen’s constant presence on his side as he experimented chipping in questions and statements that makes Senku babble on another lecture.

Humans, no matter how logical and rational they are, would always slip one way or another and for Ishigami Senku, that was when the stars burned their brightest.

He’s starting to sound like Gen. Senku sighs, _this must be the result of prolonged exposure to the mentalist._

 ~~He ignores the pang on his chest when he remembers Byakuya~~. He was going to save all seven billion people on Earth. ~~Too bad he didn’t include space.~~

The sun rises, to Senku’s annoyance. Sleep had evaded him and Senku knows the effects of sleep deprivation—focus slipping from his fingers, fatigue, physical illness when he grows older—but insomnia was a childhood friend and with the threat of everything just looming around the corner, it’s no surprise that Senku’s mind wouldn’t allow him to go to REM sleep.

Still, when Suika had given him an idea on how to get his manpower, Senku manages to think of a way to make ramen in the stone world. Thinking fast on his feet, no matter how sleep deprived he was or what situation he was in, was something Senku was really good at, after all.

Ramen. It was one of Japan’s finest inventions and people were incredibly missing out if they haven’t tasted one. ~~It’s also the food that Senku eats the most with Byakuya.~~

Making ramen from scratch wasn’t easy especially for a man like Senku. Even when he told Chrome that cooking was science, he had been exiled from the kitchen long ago when he did “experiments” on cooking. Look, third grader Senku didn’t know much about the chemicals that shouldn’t be mixed in the kitchen. Still, Senku thought he’d be able to make a tastier ramen than this.

But well, it works. Sort of, especially to the people who never had it before which means almost everyone in the village.

“Ah,” Someone says amidst the noise, voice high pitched. “This is making me thirsty for a cold drink, like a cola for example.”

Before Senku can blink, Kohaku, Ginro and Kinro has their weapons aimed at the newcomer and yet it doesn’t faze him. When Senku turns and looks at the newcomer, there’s hidden amusement in those light blue eyes as his sharp tongue wiggles him out of Kohaku’s dagger.

117,391,710,642. The clock in his mind stops counting when light blue eyes finally meet his and a smile blooms on the newcomer’s face.

Senku doesn’t even know he’s grinning, until he feels the corner of his lips rise up even more. “Mentalist.”

Gen, who has never flinched at Kohaku, Kinro and Ginro’s weapons are pressed down on him. Gen, whose sharp tongue and even sharper voice manages to convince Kohaku to lower her weapons. Gen, who looks at Senku with amusement on his eyes like he wasn’t being threatened just seconds ago. Gen, who shouldn’t look as good as he is with that dual-toned uneven hair and purple haori. Gen, whose smile turns into something _softer_ and more genuine when he meets Senku’s gaze.

There’s a teasing glint on Gen’s eye as he throws back Senku’s words, “Scientist.”

117,391,710,648.

“Why are they just staring at each other?” He hears Ginro whisper and against all odds, it makes Senku snort.

Kohaku looks at Senku, her guard still up against Gen. “Do you know him Senku?”

Senku snorts. “He’s a magician who used to write trashy psychology books.”

“Senku-chan,” Gen whines but Senku knows that he isn’t offended by it, not even one bit. “I’ll have you know that those books are sold out in Japan during the first printing!”

“Now that you’re here,” Senku grins cockily, ignoring Gen’s affronted look at being ignored. “I’ve got added manpower. There’s no such thing as a free lunch, after all.”

“Ah, such a slave driver as usual, Senku-chan.” Gen whines but the smile on his face doesn’t waver.

Senku can pretty much come up with two conclusions as to why Gen was here. One, he managed to break out of the stone all by himself and managed to find the village by chance. Two and the most likely one, Tsukasa had revived Gen after hearing of his mentalist skills and asked Gen to look for Senku and confirm if he was really dead.

“Ah,” Gen sighs, voice a mere whisper as he pushes the handles for their furnace. “Right, this body isn’t used to this yet.”

“Used to what?”

“Being worked to the bone, of course.” Gen replies, without missing a beat. There’s a pause in his movements and Gen’s cocky smile appears as he returns Senku’s gaze. “You really are a slave driver, Senku-chan. Tsukasa’s Empire is much more lax than this.”

Kohaku immediately has her knives out. “You—!”

“How’s Taiju and Yuzuriha?” Senku cuts Kohaku off, already knowing Gen’s objective. If Senku hadn’t met Gen before the petrification, Senku would’ve been on his guard especially since one word from Gen and Tsukasa and his army could come marching by tomorrow. If Senku hadn’t met Gen, Senku would’ve retained his first impression of Gen—shallow, a fraud with trash books.

But Senku knows Asagiri Gen—knows that most of his earnings go to charity, knows that Gen hums in the morning while making breakfast, knows that Gen’s specialty is misdirection and manipulation but he has never used it on Senku, knows that Gen with all the façade he does, was someone who cared a lot. If he didn’t, Gen wouldn’t have bothered to bring food meant for two when he comes home from work. If he didn’t, Gen wouldn’t bother to help Senku on his experiments and remind Senku to eat and take a break. If he didn’t, Gen wouldn’t bother to help Senku with the furnace and would immediately go back to Tsukasa once he saw Senku.

Gen hums. “They’re fine. Yuzuriha’s better at acting than Taiju though I didn’t think anyone would be dumb enough to think that it takes her one whole night to finish sewing but well, everyone in Tsukasa’s Empire is either dumb or dense.”

Ah. So Gen knew the reason why Yuzuriha was with Tsukasa then but aside from him, no one else has managed to find out. It’s not surprising, not when it’s Gen they were talking about.

Gen sighs, “What did you even do to Tsukasa-chan to make him doubt the things he saw and did with his own hands, Senku-chan?”

Senku snorts. “Who knows with that guy. Maybe I’m just unforgettable.”

Gen turns to look at him, lips parted in surprise before he laughs. “Senku-chan, I’m a terrible influence on you. You really said that with a straight face.”

“So,” Kohaku whispers from beside him, looking at Gen suspiciously. “He’s an ally, right? He wouldn’t tattle to the long-haired man?”

Senku looks at Gen. He’s humming again and he looks like he’s enjoying the manual labor for someone who kept on whining. “Yeah,” Senku nods. “Ten billion percent an ally.”

“Don’t go ruining my reputation now, Senku-chan.” Gen says because _of course_ he’s paying attention to their conversation. “So, what are you making this time?”

“Magnets.”

“Magnets?” Gen hums. “Oh, for the generator.”

Senku raises a brow. He’s pretty sure that he didn’t tell anyone that he was going to make a generator and there are a list of things in the modern world that require magnets.

“Shouldn’t you be getting ready, Senku-chan?”

Senku pokes a hand on his ear. “Yeah yeah but we’re missing a fundamental piece. We need lightning.”

Senku had forgotten about his stupid Senku luck. As soon as he utters the words, flashes of lightning emerges from the sky which is—shit, bad timing. Ten billion percent. They still didn’t have everything ready yet.

“It’s a race against time, huh.” Senku runs his hand through his hair before he looks over to Chrome, “Melt the—”

“Already on it, Senku-chan.” He hears Gen say making Senku look at him in surprise. “You need the copper wire for the magnets, right?”

Magma suddenly comes, glaring and shouting at them with a threatening aura. Senku would rather not fight them especially not now when they were racing against time. They needed a distraction of some sorts, just for ten seconds to finish their lightning rods.

A distraction. Chrome couldn’t use his flame test reaction with the heavy winds and Kohaku would duel them without thinking. Gen—

Senku looks over to Gen, already finding the man looking at him. “Gen!”

“Yes yes, I’d rather not do this but guess I have no choice again,” Gen sighs, cutting off Senku’s words like he knew what Senku was thinking before he crouches next to Suika. “Do you have any flowers by chance, Suika-chan?”

Suika gives Gen a bunch of flowers and before long, Gen’s meeting Magma halfway through the bridge. Gen walks with the flowers on his hand, posture lax and expression carefree as he places the flowers in between his fingers. Gen was thinner and shorter than Magma but Senku leans back on the bridge, crossing his arms on his chest as he watches Gen fool Magma.

“The flowers…” Kohaku hums. “Is that enough to fool Magma?”

“It’s a common sleight of hand trick. It’s called back-palm and magicians use it all the time.” Senku grins. To be honest, Senku has never really watched any of Gen’s shows even back when they were roommates but there was a reason that this guy was a rising mentalist back in their time. “Not bad, mentalist.”

They manage to make in time, creating magnets for their generator. As the skies clear and Senku grabs the magnets, Senku thinks of how fluid and how easy Gen fits into the Kingdom of Science, as if he already had a space there in the first place and it was just waiting to be filled.

When Gen smirks back at him, Senku feels his stomach churn.

Huh. Must be his stomach not used to foxtail ramen.

*

When Kohaku jumps out of Chrome’s hut with her knives, eyes sharp and movements tense, Senku and Chrome immediately climb down to follow. Senku was the worse between all of them in physical activities so it’s no surprise when he arrives last.

Senku puts his hands on his knees, looking down on the ground as his chest heaves up and down.

“…Gen?”

Suika’s voice makes Senku look up in surprise. He feels his throat dry up, looking at Gen’s body full of blood and bruised all over.

“It’s no use,” He hears Kohaku’s defeated voice. “He obviously died instantly.”

 _No._ Senku tries to focus but he feels like his throat had dried up and feels like someone had doused cold water on him. _No._ Senku closes his eyes, focuses on his breathing. One. Two. Three. Four. Five. Six. Seven. Eight Nine. When he opens them again, he looks at Gen’s body and buries down the overwhelming coldness seeping through his bones.

In an instant, Senku’s eyes land on Gen’s chest—which was going up and down. Barely there but Senku _knows_ Gen is breathing. Looking closer, Senku pulls the spear out of Gen’s chest and he feels his lips pull up in a grin when he sees a blood bag attached to the spear.

“Blood bags?” Chrome says, holding up another one. “It’s all over his body!”

“And shells too.” Suika says, holding up a cracked shell.

Senku feels the warmth come back to him, slowly chipping away the coldness Senku felt at the thought of Gen’s death. He grins. “You really are a magician through and through, Gen. Not bad, mentalist. Not bad at all.”

“Let’s get him inside!” Chrome says and slowly, they managed to place Gen on Kohaku’s back. She’s slow in walking, careful not to move Gen too much. “He might’ve protected himself with shells and blood bags but he’s still injured.”

Senku thinks of the plants he’s seen in Chrome’s collection. Geranium thunbergii. Mallotus japonicas. Rhizome of Panax japonicus. Cnidium rhizome. Not for the first time, Senku is amazed at the amount of useful things that Chrome had found, even when he didn’t know what it was for. Thankfully, he could treat Gen’s wounds with the plants in Chrome’s shed.

“Who could’ve done this?” Kohaku murmurs as she slowly places Gen on a makeshift bed, assessing his injuries. “The shells protected his chest and his stomach along with the blood bags but he’s bruising all over. It must be painful to even breathe.”

Senku crushes the leaves, trying to get the image of Gen’s bloody and lifeless body out of his mind. “He’s going to be fine. The mentalist is too stubborn to kick the bucket like this.”

Senku places the crushed leaves on a cloth before he gently places it to the bruises around Gen’s body. Kohaku had wiped off the fake blood but there were still scratches of blood in Gen’s body.

“Senku-chan.” Gen wheezes and Senku stops. Gen’s chest is heaving too fast, lips trembling as he tries to get the words out of his mouth. “I… can’t… stay… here… long.”

“That’s a problem for another day.” Senku says. _One step at a time_. “Right now, focus on healing.”

Chrome looks at Senku in confusion. “What does he mean he can’t stay long?”

“If he doesn’t return,” Senku knows what Gen means, even without him saying it outright. He has always been able to read between the lines and it’s easier with Gen. He knows the hidden meaning between Gen’s words and Gen knows exactly what Senku means with just one look shared between them. “Tsukasa might come down here himself and then we’ll be doomed.”

Horror is written all over Chrome’s face. He knows how powerful Tsukasa is, not only because Tsukasa killed Senku but also because he had found out how Tsukasa managed to go toe-to-toe with Kohaku and come up on top.

Senku focuses on making treatments for Gen. He knows he has to think of something to ensure Tsukasa doesn’t come to the village, not when the Kingdom of Science is barely even here but that’s a problem he needs to think about tomorrow. Right now, Gen needed his help.

Senku looks at him and sees his chest slowly moving up and down.

 _He’s alive._ Senku’s grip on the mortar tightens and he crushes the leaves with force. _He’s alive._

Senku had declared that he would save all seven billion people on the planet. He was not letting Gen die right in front of him. Not on his watch.

“Hey, Senku-chan.” Gen wheezes, breath soft and almost inaudible. “The stars… are really… pretty, aren’t they?”

Senku turns to him, raising a brow.

“We couldn’t see it clearly back in our time but it really is pretty.” Surprisingly, Gen’s voice is soft, sitting up as he gazes at the night sky. “The moon…”

“What about it?” Senku frowns. “Stop moving. You’ll aggravate your wounds.”

Gen laughs. Even when Senku can pretty much guess what Gen was thinking, the sudden laughter still manages to surprise him. “I’m fine, Senku-chan. The shells absorbed most of the attacks. I’m just a bit uised-bray. Now help me up, I need to go back to Tsukasa-chan.”

“Gen.”

Neither of them moves, stuck in a standstill with one another.

“Any time now Senku-chan or would you like me to bring Tsukasa to your doorstep?”

“Gen.”

Gen sighs. Stubborn. Unrelenting. “Senku-chan, do you know the first rule of being a magician?”

Senku frowns at the non-sequitur but he answers with the first thing that comes in his mind, “No. But you’re a ten billion percent fraud, how would you know that?”

“Rude.” Gen pouts, his voice going octaves higher. “I’m a master with sleight of hand, thank you very much.”

“Uhuh,” Senku pops in his finger on his ear. “So what is it then, the first rule?”

“It’s to always have your poker face on!” Gen grins and there’s a pop before paper of different colors come flying in the air. “To conceal behind a mask and never let the audience deduce and see what you’re feeling. But let me tell you a secret, sometimes magicians break the rule when they get cornered and then with that one crack, they break. The greatest advantage and weakness of a magician is their composure. Human mind is a complex thing, after all. Feelings. Thoughts. Those simply cannot be controlled.”

There’s a theory about that that Senku remembers in passing.

“Morsella’s passive frame theory.”

Gen looks at him in surprise. “You know about that, Senku-chan?”

Senku hums. He had glossed over it after being interested in reading about mind control. Senku’s first love would always be the hard science—chemistry, physics—but Senku, at some point, had been interested in the mind too.

“In passing.”

“It’s an example,” Gen says, grabbing the medicine that was stuck to his face. “Stimuli in the environment can determine what we end up thinking and once an action is implemented based on the thoughts influenced by the environment, it’s difficult to override.”

Senku blinks, trying to take in Gen’s words. He tilts his head and frowns. “Is there a point to this or are you just trying to distract me?”

“Moi? Distract _you_?” Gen points to himself with the most innocent look Senku has seen in an adult’s face. If he didn’t know Asagiri Gen and if Senku wasn’t… _Senku_ , well, he would’ve fallen for it. “Of course not, Senku-chan. Unlike those amateurs, I can keep everything under control especially when I’m on pressure so there’s no need for you to orry-way.”

“Who said I was worried?” Senku deadpans.

Gen’s laughter echoes across the room. Like this, with the moonlight illuminating the room, Senku can see the softness in Gen’s eyes but there’s something else there too, something that Senku doesn’t recognize.

“I’m just saying, Senku-chan. Your thoughts cannot be controlled especially after what you’ve been through,” Gen says and he tries to move his body eliciting a glare from Senku. “It’s alright to admit that you’re worried—maybe not for me but for your friends. Tsukasa-chan is very scary, isn’t he?”

Senku sighs. “Illogical. Why waste on drivel things?”

“Your feelings aren’t illogical, Senku-chan.” Gen rolls his eyes. “Rationality and emotions aren’t actually mutually exclusive but people make it like they are.”

Senku raises a brow, suddenly curious. “Well, then, oh great mentalist, surprise me because evident suggest that emotions affect how people make decisions.”

“I’m going to ignore the sarcasm on your tone,” Gen deadpans, frowning at his bloodied and torn up purple haori. “Did you know that in the field of experimental psychology, emotions and cognition was known to be “divide and conquer” and it wasn’t in the last decade that studies have connected both of them together?”

Senku hums, waiting for Gen to continue.

“It wasn’t until 1999, I think, that it was realized that both systems were distinct but also interacting.”

“Doesn’t that just proves my point?”

Gen ignores the jab and for some reason, he manages to find a needle in the middle of the room, sewing his purple haori together. “But you see Senku-chan, there was this study by a British school that said that rationality comes from voiding your emotions rather than the absence of emotions.”

“So you’re saying that they’re connected but they aren’t mutually exclusive.”

“Ding ding ding,” Gen grins. “Ten billion points to you. People usually mistake rationality for not having emotions because emotions cloud your judgment but your emotions are the ones that make you human.”

“You’ve never tried that mentalist shit on me.” Senku tilts his head, frowning. “Why start now?”

“Because if you keep that bottled up, someday the cup would overflow and it would break from the pressure inside.”

Senku throws him his blanket. Kohaku had gotten it for him to ward off against the coldness during the night. “Fine. But stay for the night. You can go back first thing in the morning.”

“You’re just saying that to end this conversation about emotions.” Gen sing-sang but accepts the blanket anyway, wrapping it around himself and humming slightly. “Rationality aside, it’s fine to let your guard down sometimes and let yourself feel. If you don’t want to show it to me then show it to the people you trust.”

“For a mentalist, you’re also dumb as fuck, Gen.” Senku says, before he can even help himself. Did Gen really think that Senku didn’t trust him? He files that information for later, burying the conclusions his brain had instantly come up with when it’s safe and Senku was ten billion percent certain of it.

“Hey rude!”

They—or rather, Senku works in silence as Gen continues to hum softly under his breath. He still has plans to think of, after all. Hurdle number one had been cleared with Gen returning to Tsukasa to tell him that Senku was dead. Now for his second hurdle was getting his manpower to create his weapons of science to trump Tsukasa.

Once the sun comes up, Gen slowly moves, folding the blanket and placing it on his sides. Senku stops, turns to look at him and nods.

They don’t need words.

117,391,710,649. The numbers continue in his head. The same numbers that had halted momentarily when he met Gen again in the stone world.

117,391,710,650. He counts as Gen climbs out of Chrome’s shed.

117,391,710,655. As Gen walks to the forest.

117,391,710,657. As Gen completely disappears. Back to Tsukasa.

Senku takes a deep breath and focuses on his work.

When Senku wins the Grand Bout out of sheer luck—he doesn’t know if he should be thankful to his stupid Senku luck or not—he finally manages to click the pieces together. Why Kohaku and Ruri had foreign blood. Why the symbol on their village was a star. Why the village was called Ishigami village and what had happened to Byakuya and all the crew members that went to space.

As Senku was frozen in the darkness, Byakuya had been fighting to rebuild humanity. As Senku stayed in one place and thought of things to keep himself awake, Byakuya had passed down the torch of saving humanity to him.

As Senku counted and counted and _counted_ , Byakuya already passed on.

Ruri takes him to the grave of their founders, laying flowers on Byakuya’s. When she leaves, Senku doesn’t know why but Gen’s words echo through his mind: _someday the cup would overflow and it would break from the pressure inside._

For the first time since his arrival in the stone world, Senku _finally_ lets go of the deathlike grip he has on his emotions and lets himself mourn at the loss of hearing about Byakuya’s death. He knows it’s illogical because crying would never bring Byakuya back, nothing would ever bring Byakuya back but as he stares at the gravestone, Senku feels his chest growing heavier and tighter and suddenly he remembers—

He remembers the unconditional support Byakuya had given him ever since he was young. He remembers the happiness bubbling in his chest when he enters his room full of equipment’s, from telescopes to beakers to lab googles and remembers the warmth on his chest when he concludes that Byakuya had sold his car to give Senku the push he needed to see the stars he wanted so much.

He remembers the unwavering confidence Byakuya has in him, no matter what experiment he was doing or how many explosions that had happened because of his curiosity.

Senku had never thanked him, not for his unconditional support, not for taking Senku in, not for helping him give the boost he needed. Senku had never thanked Byakuya because they weren’t one for sentimentalities—or at least Senku wasn’t.

~~Senku had never thanked Byakuya for everything he had done and now, he can’t ever do that no matter how much Senku wishes for it.~~

Senku wipes the tears from his eyes and looks at the night sky. “Heh. Thanks, old man. Without your gift, I would’ve been screwed.”

Senku knows without a doubt that Byakuya wouldn’t want him to wallow about his death. He has seven billion people to save, right now, he should focus on that.

Speaking of that.

Senku arrives at the village, immediately looking for Gen. “So let’s hear it, mentalist. The reason why you’ve come back so early.”

“I brought you two weeks of time, Senku-chan.” Gen says, sighing. “You owe me a lifetime supply of cola, you know.”

“Yeah yeah, so?”

Gen looks at him, the grin on his face smells like impending doom. “They’re coming. Tsukasa and his army. He sent Hyoga-chan along with a few lackeys and the power Hyoga-chan has with his kudayari is _almost_ on par with Tsukasa-chan.”

When Ginro comes bustling in the village, yelling about intruders, Senku feels a headache about to come.

Tsukasa as usual had dampened the celebration.

*

117,391,843,243 seconds on the dot is when Gen gets exposed as a traitor and officially joins the Kingdom of Science. Gen fits right in their merry band of a team and Old Man Kaseki seems to like him, even when all Gen does is push his buttons.

Gen had always been an enigma—for Senku at least. At first, Senku had thought nothing of Asagiri Gen knowing that their paths wouldn’t cross. After all, Senku was never interested in psychology or magic for that matter. But when he had met Asagiri Gen, there were puzzle pieces that didn’t fall into place and sometimes Gen doesn’t make any sense. When he’s with Senku, most of the time, he manages to guess what’s on Senku’s mind or Senku’s next course of action but during those times, there’s a fleeting emotion on his face that Senku couldn’t quite read. He indulges Suika with his magic tricks, no matter how many times the child asks for it. He talks and fills the silence when he’s with Kaseki talking about everything but also nothing—he was like a blurry glass where you could see the person on the other side but not clearly.

Asagiri Gen has a mouth that could weave lies but he has never used it on Senku—if it’s done unconsciously or if he knows that Senku would see right through him is still unknown.

Sometimes, Asagiri Gen does not make sense. He would tell Senku something or says words in passing that would make Senku stop and wonder for a second but Gen had already moved on.

_Exhibit A:_

“Wakey wakey, Senku-chan!”

Senku blinks, taken aback at Gen suddenly appearing in front of him with a flashlight turned on his face. “Gen?”

“C’mon. It’s New Years. Let’s all watch the first sunrise together. Changing the mood and refreshing everyone’s spirits is kind of my job, isn’t it?”

“You mentalist are a pain in the ass.”

“Well,” Gen says as soon as Senku touches the ground. Gen has his hands hidden underneath his sleeve, like a magician with too many secrets. “If you’re stuck maybe a flash of light would come to you if you take a breather.”

Senku complains but he comes down nonetheless. He’s not the only one down about not being able to do the cellphone, of course, not when all their efforts would go down the drain. Yet there’s confidence in Gen’s words, like he knew that Senku and their efforts wouldn’t be in vain if they watched the sunset together.

Which throws Senku off.

Together with people from the village, they climb up to the cliff where they could watch the sunrise without any hindrance.

“Our internal clocks are messed up after the petrification though.”

Senku yawns. “Just remember how many days you’ve lived.”

Kohaku snickers. “Why the hell would we remember that?”

_Exhibit B:_

Gen looks at him and hums. There’s a knowing glint on his eye, “I don’t think anyone would remember that except you Senku-chan. So, how many days has it been?”

It’s a throwaway question. Something that isn’t unusual at all. But there’s something in that question that makes Senku feel like he’s missing a piece of the puzzle.

Gut feeling? Absolutely not. Senku doesn’t rely on something as inaccurate as that.

If Senku were to pick something, maybe it had been because of Gen.

“6269 days.”

Gen hums. The sun rises. The world continues to rotate but there’s something that Ishigami Senku is missing.

_Exhibit C:_

When Magma blindfolds him and carries him all the way to the village, Senku could sum up five logical conclusions to why this happened. Still, when he hears Kohaku say, “Ha! It’s pointless to beg, Senku! Everyone in the village is on with this.”

Ah. The most logical and rational choice then. If they deliver Senku to Tsukasa, their village wouldn’t be in danger. Still, he wonders what Gen’s role to all of this is. It’s not like he can defect back to Tsukasa’s Empire and he’s ten billion percent sure that the mentalist would rather rot than go back to Tsukasa.

“Fear not, Senku-chan.” Gen says and it’s all Senku can focus on with the blindfold on his face. Take one sense away and the other heightens. “We’re not turning you in to Tsukasa-chan or anything.”

And he says it so casually, like he already knew what Senku was thinking about.

Before Senku can analyze it all, he feels the blindfold around his eyes loosen.

“Oho! It’s the fourth of January—“Stone Day!”

“We heard it’s your birthday, Senku! From all of us, here’s your birthday present!”

When the blindfold finally falls from his eyes, Senku feels warmth bubbling in his chest—the same warmth that came when he opened the door to his room and it was suddenly full of equipments. Venus is visible, barely and the quality is shit, but it’s there and Senku can see it.

“A telescope,” Senku feels his throat dry up. “No, an observatory.”

 _“I’m going to space.”_ When Senku had declared that as a fifth grader with no experience or knowledge about science, Ishigami Byakuya had given him his unconditional support, giving Senku the chance to see the stars he loved so much. At the very start of it all was Ishigami Byakuya.

It would be a lie if Senku would say he had never thought of making a telescope before. Not just because it was rational and could be used once they finally battle Tsukasa but also because he wanted to see the stars again.

~~The stars were one of the things that reminded him of Byakuya.~~

Ishigami Senku will claim that he is a man of science, of logic and of reason and that was the irrefutable truth. But also, Ishigami Senku is only human and emotions and sentimentality was still a part of him, even when he tries his hardest to bury them down.

He pats on the telescope. “Dang! You guys did a great job! This is really practical. We can totally use this as an observation tower against the Tsukasa Army.”

“Uh… yeah, I guess.”

He hears Gen sigh. “A very rational opinion as usual.”

Senku taps on the telescope. It’s different from Senku’s first one—that one had been given by Byakuya; smooth, precise and clear. This one—had been handmade by Gen and the villagers; smooth, slightly unclear but it’s the same. It’s the same instrument that gave Senku his stars back.

Senku snickers. “A guy doesn’t even mention his birthday. How did you know it was today?” He remembers Gen asking him how many days he had lived. _Interesting._ “Oh, I guess I incriminated myself huh. But without knowing how long I was petrified, you wouldn’t be able to do the math.”

“Oh? You don’t remember?” Gen grins at him. “You wrote it down. The date that you were depetrified. Next to the cave of miracles, right where you woke up, Senku-chan.”

There’s a nostalgic smile on Gen’s face, as if he was remembering something amusing. He looks up at the sky, gaze warm and his voice was low yet there was a certain kind of softness to it. “More than a little, I already liked you, Senku-chan. Forget about what I stood to gain from it. It’s probably the same for everyone in the village.”

Gen turns to him and there’s warmness in his gaze, light blue eyes shining in the moonlight. “Guess you’ll probably say this is gross though, huh?”

“Yeah…” Senku replies yet he couldn’t hide the softness in his tone. “Gross dude.”

Gen laughs. “Right?”

As Senku looks at him, he realizes that Asagiri Gen does not make sense.

They get busy during the day to finish up the cellphone. They were racing against time after all. They had to burn the tungsten and make the toothpaste needed for their cellphone.

Senku files all the information he has for later and maybe he’ll finally get the answers he wants from Gen.

He finds Gen on the observatory, glancing up the stars. After a long day of hard work, Senku wants to lay down and sleep for eight hours. When Senku enters, Gen pats the space beside him without even glancing once at the doorway.

Senku grunts but sits down next to Gen anyway, their shoulders brushing slightly.

“So,” Gen says, breaking the silence. “What do you want to ask, Senku-chan?”

Senku snorts. “Am I really that obvious?”

“Only to me~”

“I don’t know if I should be happy with that.” Senku frowns. Well, Senku was always straight-forward, no matter who he was dealing with. Even a mentalist of Gen’s caliber wouldn’t be an exception. “April 1st, 5738.”

Gen hums. He’s maintaining his calmness, befitting a mentalist. Senku remembered when Gen had told him that the first rule to being a magician was having a poker face. He realizes now, while he looks at Gen, was that this was the first time Gen had turned on his poker face when he was with Senku.

Senku doesn’t know what to do with such information.

“How did you know about it?”

“A coincidence, perhaps?”

Senku raises a brow at him. “You’re a mentalist. Surely you can lie better than that.”

“I got caught?”

“A coincidence, really Gen?” Senku deadpans. “Then, how did you know January 4th was my birthday?”

“I told you—”

“I gave you the wrong date.”

Gen whips his head to look at him. He looks like he’s trying to remember where exactly he had slipped up before his eyes widen in realization. “6269, you said.” There’s a smile on his face. “If I were to do the math on that date, your birthday would be on January 5th, not 4th.”

“And yet you still managed to get it.”

Before Senku can blink, Gen’s already laughing. Full blown laughter. The type of laughter on which the mentalist has tears on his eyes. He lays down on his back, looking at the stars when he finally composes himself.

“Ah,” He says, a small amused smile on his lips as he meets Senku’s gaze. “I really can’t win against you, Senku-chan.”

Senku grins back at him. “It was a nice try.”

Gen closes his eyes and Senku does nothing but wait for him. He grabs the telescope, looking through the glass as he waits for Gen to tell him.

“Well,” Gen finally says but Senku doesn’t turn to look at him, not when he could hear Gen’s voice slightly breaking. Gen clears his throat, “How do you feel about time travel, Senku-chan?”

Senku’s brows furrow before he turns to look at Gen. “Statistically, there are no current records of successful time travel. Everything is conspiracy, theory. Gödel, Earman and a couple of other physicist claims that it generally creates a paradox that could alter the future. Wheeler and Feyman on the other hand believed that nature was continuous and no matter what may be altered, nature will run its course, the most common example of that is throwing a pebble in the river and creating ripples but still the river runs continuously.”

Gen scrunches his nose. “You sound like one of those research papers in the internet, Senku-chan.”

“Well, in theory, it _is_ interesting.” Senku shrugs. “But not possible even with the technology on our time. The effects of going back in time would deter the human mind and no one would be able to escape unscathed. Plus, no one knows exactly how to make a human turn back in time.”

Gen laughs. “Right?”

Senku knows how to read between Gen’s lines and for any other person, it might sound like what Gen had said was utter bullshit, but even with the easy lies and haunting taunts that come out of Gen’s mouth, Senku knew that Gen wouldn’t lie to him—especially not when it’s something like this.

“So you already know who I am, before this all happened.” Senku murmurs, more to himself than to Gen. “You already know when I was going to wake up—so you know about the petrification incident.”

When Senku turns to look at Gen, who had turned quiet, he finds the latter staring at him in surprise. “You’re taking this awfully well.”

“You’re not the type to lie to my face about something like this, Gen. Besides, I trust you.” Senku replies and he thinks of the times where he felt like there was something _off._ Finally, the puzzle pieces are forming in his head. “Did you try to change anything?”

“Ah, you noticed that huh. I didn’t mean anything by that, Senku-chan. We’ve only been with each other for six months before we got petrified, after all.” Gen winces. “Yes well, before I didn’t go to college. I didn’t meet you, not until we got petrified and Tsukasa sent me to verify if you were really dead.”

“Huh,” Senku remembers all the times that made him stop. Their first meeting—Senku wasn’t sure if he heard it right, not when his ears were slightly damaged from all the explosions he was prone to—but Gen had called him by his name. The tattoo on his chest which is the exact date of Senku’s revival. Gen knowing the things Senku would ask even before he could say it. “Everything makes a lot of sense now.”

“I would’ve thought you’d say that everything was bullshit because time travel doesn’t exist.”

Senku shrugs. “When I woke up from the petrification, the first theory in my mind was aliens petrifying humans because we looked stupid in their eyes.”

Gen blinks at him. Once. Twice. Thrice. Before a smile emerges on his face. It’s not the same cocky smile he saw on Gen’s trashy magazines, it’s the kind of smile Gen gives when he’s comfortable at something or someone, the kind of smile Senku had seen when Gen hums in the morning as Senku enters their kitchen with breakfast, the kind of smile Senku had seen when Gen’s helping out with his experiments chipping in questions and statements to indicate he was listening—even when he doesn’t get anything at all. It’s the kind of smile Gen gives to Senku, all the time.

“Senku-chan,” Gen says and his voice is uncharacteristically soft and mellow. “The moon is beautiful, isn’t it?”

Senku stops. Exhilaration. Euphoria. Racing heart. Trembling.

_Oh._

He looks at the telescope and sees the glow of the moon, shining so brightly. There’s still so much to be done, so many things to do but just for a moment, Senku indulges himself with this.

The silence is comfortable, as it always is with both of them.

*

When Senku hears Byakuya’s voice again, he feels like he’s being stabbed in the chest by a spear.

He’s not alone now, he knows that, not when he has the whole village with him—Chrome, Kohaku, Kaseki, Ruri. Not when he has Gen, the only current modern man aside from Senku in their Kingdom of Science. Not when he knows that wherever Taiju and Yuzuriha were, they’d always trust him.

He doesn’t feel lonely but hearing Byakuya’s voice feels like he is but at the same time, it also feels like closure.

He ignores the way he hears Byakuya’s voice break and waver before Byakuya laughs it off and Lilian’s voice replaces his. With every line Lilian sings, Senku remembers the hardships he went through for a year and a half. With every melody that comes, Senku remembers the old days where he and Byakuya would go ramen hopping, testing out different ramen from the stores near their house.

Senku was never one for sentimentalities and his father knows exactly just that ~~but maybe just once, Senku wanted to hear one.~~

When Senku arrives at the observatory, he’s not surprised to see Gen already using his telescope. It’s like an unspoken rule at this point—it wasn’t just Senku’s telescope, it was Gen-and-Senku’s telescope seeing that Gen would often come in the evenings and just watch the stars while Senku was cementing his plan.

Later, Senku would blame it on the stress but for now, he doesn’t hesitate as he walks toward Gen, plopping down behind him before leaning his back against Gen’s. It’s a comforting presence—the warmth of Gen’s back, the squawk he releases as he whines Senku’s name but makes no action to move him, the smell of flowers mixed with the old smell of rocks.

Gen starts humming and he never pushes. He calls out Senku on his bullshit or when he’s trying to lift up the morale. He usually taunts others and manipulates them to help Senku in any way he can but Gen never pushes Senku. He waits and waits and _waits_ until Senku speaks up first, until Senku tells him first.

Senku takes a deep breath and plunges down hard, “It’s not supposed to be this hard.”

Gen continues humming and for some reason, it’s a balm to the wound Senku is bearing right now.

“In my mind, I already knew, even before I learned about Ishigami Village, even before I broke out of the petrification. It’s been 3,718 years. There was no way that he would still be alive. My mind already knew. The evidence was presented right in front of me.” Senku exhales. “And yet…”

“Just because you know doesn’t mean it hurts less.”

Senku leans his head on Gen. “Yeah. Completely illogical, isn’t it?”

“Most humans are, Senku-chan.”

“I’ll never be able to thank him for everything,” Senku says and he snorts. “He’d probably just say save humanity and we’re even though.”

“He sounds like you.” Gen laughs. “I think he already knows, Senku-chan.”

Senku closes his eyes. With this, he can focus on Gen’s warmth against his back and the smell of flowers enveloping him. With this, Senku feels at peace. He relaxes against Gen, feeling the earlier fatigue and emotional turmoil slowly leaving him.

Senku knows exactly how many seconds have passed but it still feels like hours as he basks in the warmth of Gen and remembers hearing Byakuya’s voice for the last time. It feels like hours before Gen finally spits out what he was thinking, breaking the silence when he says Senku’s name.

“Hypothetically,” Gen continues, not even giving Senku a chance to respond to his name. “If I told you I love you, what would you say?”

“Hypothetically,” Exhilaration. Euphoria. Racing heart. Trembling. Senku knows these too well. “I’d tell you _I know._ ”

He hears Gen’s breath hitch before his shoulders shake as a chuckle emanates through the air. “I wasn’t subtle?”

Senku snorts. “What’s subtle about telling me _the moon is beautiful, isn’t it?_ ”

“Why, Senku-chan.” Gen says, his voice betraying his relax body. “I never thought you’d be the kind to read Souseki Natsume.”

“Usually. I’d rather read the entirety of Old man Einstein’s autobiography than read stuff like that.” Senku says. “But Souseki Natsume focuses on the rapid industrialization of Japan and Japan mimicking Western culture.”

“Of course you’d read it just for Japan’s rapid industrialization.” Even without looking at him, Senku knows Gen is rolling his eyes but the obvious fondness on Gen’s voice was unmistakable. “Ah, so was the silence my rejection?”

Dopamine. Norepinephrine. Serotonin. Oxytocin. Vasopressin. Senku knows all the hormones in his body that create this kind of feeling. He had noticed the signs in himself too. Exhilaration. Euphoria. Racing heart. Trembling. Physical signs that Senku could not ignore. After all, Senku did not become a scientist to deny the evidence right in front of him.

“No.” Senku admits, more to himself than to Gen. His silence wasn’t a rejection. It was more of an acceptance, if Senku would put it into words. If he wanted to reject Gen, he would’ve done so the exact moment Gen had told him he was in love with Senku.

“But saving the seven billion people in the world is your top priority right now.” Gen finishes his thoughts.

Senku knows Gen doesn’t need confirmation but he nods anyway. Slightly. Barely even there.

“Ishigami Senku, the Prometheus of the Stone World!” Gen sing-sang, leaning back at Senku. “If it’s you, you can accomplish anything, Senku-chan.”

Both of Gen’s hands are on the floor, balancing him as Gen leans his weight on Senku. Senku tamps down the urge to put his hand above Gen’s.

He wants to.

And in this moment, that's all that matters, isn't it? Just like this, Senku can forget that the world needs saving. Even just for a moment, Senku allows himself to be selfish.

Senku closes his eyes, sighs softly as he places his hand above Gen’s.

_For now, this is enough._

Judging from the surprised yet pleased sound Gen makes, Senku knows they’re both on the same page.

(―still, it doesn’t stop Senku when years down the line, after they have finally brought back all seven billion people and established cities, Ishigami Senku brings Asagiri Gen back to the observatory. The telescope is still there, intact and never once touched. It’s a memento, a gift, a piece of himself that Gen had given back.

When Senku leans back on the window, looks at the moon before his gaze turns to Gen, who was looking at his telescope with rapt interest.

It makes Senku smile.

“Hey Gen,” Senku says and the feeling he’s had all those years ago, hearing Gen say those words are here but stronger. Exhilaration. Euphoria. Racing heart. “The moon is beautiful, isn’t it?”

Gen blinks at him, lips parted in surprise and eyes wide. He looks comically hilarious that Senku can’t help but grin back at him, feeling like his heart was beating too loudly in his chest. Then, Gen places his hands on Senku’s neck, bringing their foreheads together.

“Ah,” He says and the smile on his face is as blinding as the light from the moon. “I can die happy now.”

And for Senku, that was everything.)

**Notes for the Chapter:**

> \- "the moon is beautiful, isn't it?" from souseki natsume who pointed out that tsuki ga kerei desune (the moon is beautiful, isn't it?) means "i love you"  
> \- "i can die happy now" is the literary reply to it which was translated from the works of shimei futabatei  
> \- overuse of the strike element but who cares  
> \- what's the use of taking up psychology if i don't overuse psychological theories and make senku process his emotions in a healthier way  
> \- talking science/psychology is like sengen foreplay no i do not take criticism. both gen and senku has a competency kink. i'm glad you all agree.  
> \- i was rewatching dr stone and when senku vvisited byakuya's grave i felt like my heart was torn in two even if i already knew what would happen.

**Author's Note:**

> scream to me how bad this fic is on twitter! @ennacore :D


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